Shielded pipe for a vehicle

ABSTRACT

A weight can be reduced, and a desired bent shape can be easily obtained with the shielded pipe of the present application. An electric wire that connects a battery and an inverter is inserted into a shielded pipe arranged underneath a floor of a vehicle. The shielded pipe has a pipe body that is made of a synthetic resin material and shaped into a predetermined shape. After the pipe body is shaped, a shielding portion is formed by spirally winding a ribbon-shaped metal foil around the outer circumferential surface of the pipe body. Furthermore, the shielding portion is inserted into a heat-shrinkable tube. The heat-shrinkable tube is heated and covers the outer circumferential surface of the shielding portion in a tight contact state, thus constituting a protective portion for protecting the shielding portion.

TECHNICAL FIELD

The present invention relates to a shielded pipe.

BACKGROUND ART

In hybrid cars, for example, a battery that is mounted in a rear portion of the vehicle and an inverter that is mounted in an engine room are connected to each other using an electric wire. This electric wire is inserted into a shielded pipe to prevent noises superposed on the electric wire from adversely affecting the outside.

As disclosed in Patent Document 1 below, such a shielded pipe is generally made of metal (made of an aluminum alloy, for example). The shielded pipe is arranged along the lower surface of the vehicle and bent into a predetermined shape. Because the two end portions of the shielded pipe need to be capable of being freely bent, braided wires are connected to the two end portions of the shielded pipe. The electric wire is connected to the battery and the inverter through the braided wires.

CITATION LIST Patent Documents

Patent Document 1: JP 2007-81158A

SUMMARY OF INVENTION Technical Problem

However, since a conventional shielded pipe is made of metal as mentioned above, an increase in weight cannot be avoided. Moreover, the bending processing is not always easily performed. One might think that as a measure taken against the problem, it is sufficient to merely reduce the thickness of the shielded pipe. However, since the bent portion is flattened (crushed) and it becomes difficult to ensure a space for accommodating the electric wire, such a measure is not practical.

The present invention was made based on the foregoing circumstances, and it is an object thereof to provide a shielded pipe that is light in weight and is easily bent into a desired bent shape.

Solution to Problem

A shielded pipe according to an aspect of the present invention is a shielded pipe into which an electric wire is insertable, and the shielded pipe includes a pipe body made of a synthetic resin material, a shielding portion formed by winding a metal foil around an outer circumferential surface of the pipe body, and a protective portion formed on an outer circumference of the shielding portion.

Advantageous Effects of the Invention

With the shielded pipe of the present invention, the weight can be reduced compared with a conventional metal pipe, and since the pipe body is made of a synthetic resin, a degree of freedom with regard to the shape of the pipe can be easily ensured. Moreover, the shielding portion can be formed by merely winding the metal foil around the pipe body, and therefore, a shielding function can be easily provided.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram showing an outline of an arrangement state of a shielded pipe according to Embodiment 1.

FIG. 2 is a cross-sectional side view showing a connection portion where the shielded pipe and a metal braided portion are connected to each other.

FIG. 3 shows a manufacturing process of the shielded pipe.

FIG. 4 is a cross-sectional view showing a structure of the shielded pipe.

FIG. 5 is a perspective view showing a state in which sheet-like metal foils are wound around a pipe body in the shielded pipe according to Embodiment 1.

DESCRIPTION OF EMBODIMENTS

Preferred embodiments of the present invention will be described below.

(1) It is preferable that the shielded pipe according to an aspect of the present invention is configured such that the shielding portion is formed by spirally winding the metal foil in a length direction, the metal foil being formed in a tape-shape.

With this configuration in which the metal foil is formed into a tape-shape, even after the pipe body is bent into a predetermined bent shape, the metal foil can be finely wound along the bent shape. Therefore, it is easy to uniformly ensure a shielding function of the shielded pipe over the entire length.

(2) The protective portion may be constituted by a heat-shrinkable tube that sheathes the pipe body.

With this configuration, it is possible to prevent corrosion in the shielding portion 7 by covering the shielding portion 7 with the heat-shrinkable tube.

(3) Moreover, the protective portion may be a film that is laminated on the outer circumferential surface of the shielding portion and have a rustproofing function.

It is also possible to prevent corrosion in the shielding portion using such a film that is laminated on the outer circumferential surface of the shielding portion and has a rustproofing function.

Embodiment 1

Next, Embodiment 1 in which a shielded pipe of the present invention is embodied will be described with reference to the drawings. This embodiment is applied to a wire harness WH that connects a battery 3 mounted in a compartment on the rear side and an inverter 4 mounted in an engine room in a hybrid car.

The wire harness WH includes a plurality of electric wires. A predetermined section of the wire harness WH in the length direction is inserted into a shielded pipe 1. The shielded pipe 1 is arranged underneath the floor of the vehicle body and bent into a predetermined bent shape.

The ends on one side of metal braided portions 2 are connected to the two end portions of the shielded pipe 1, respectively, and the ends on the other side of the metal braided portions 2 are connected to the battery 3 and the inverter 4, respectively.

The metal braided portions 2 are formed by braiding copper-based individual metal wires whose surface is plated with tin into a mesh structure having an elongated tubular shape, for example. The wire harness WH drawn out from the shielded pipe 1 is inserted into the metal braided portions 2. Terminal fittings (not shown) are connected to the end portions of the electric wires included in the wire harness WH. As shown in FIG. 2, the end portion of the metal braided portion 2 is connected and fixed to the end portion of the shielded pipe 1 using a crimping ring 5.

As shown in FIG. 4, the shielded pipe 1 of Embodiment 1 has a three-layer structure. A pipe body 6 is arranged on the innermost layer side. The pipe body 6 is made of a synthetic resin and is formed into an elongated pipe shape that has two open ends. The pipe body 6 extends roughly in a front-rear direction of the vehicle, but it is partially bent three-dimensionally to bypass projecting portions and recessed portions underneath the floor of the vehicle or to follow projections and recesses.

A shielding portion 7 for providing the shielded pipe 1 with a shielding function is arranged in the intermediate layer of the shielded pipe 1. The shielding portion 7 is formed by spirally winding a tape-shaped metal foil 8 around the outer circumferential surface of the above-mentioned pipe body 6. The winding of the metal foil 8 is started at one end of the outer circumferential surface of the pipe body 6 in the longitudinal direction, and is ended at the other end. The metal foil 8 is made of an aluminum alloy, for example, and a bonding layer that can adhere to the outer circumferential surface of the pipe body 6 is formed on its back surface. In this embodiment, the lateral edge portions of the tape-shaped metal foil 8 overlap each other in the winding process, so that the outer circumferential surface of the pipe body 6 is not exposed. It should be noted that the shielding portion 7 is grounded at an appropriate position. In this manner, the shielding portion 7 is formed on the outer circumferential surface of the pipe body 6.

A protective portion 9 for the shielding portion 7 is arranged in the outermost layer of the shielded pipe 1, that is, on the outer circumferential surface of the shielding portion 7. The protective portion 9 of this embodiment is formed of a heat-shrinkable tube 10. The heat-shrinkable tube 10 sheathes the pipe body 6 provided with the shielding portion 7, and is formed to be long enough to cover substantially the entire length of the pipe body 6. When the heat-shrinkable tube 10 is heated, its diameter is reduced, thus making it possible to bring the heat-shrinkable tube 10 into intimate contact with the outer circumferential surface of the shielding portion 7 and to protect the shielding portion 7.

It should be noted that the heat-shrinkable tube 10 used in this embodiment is made of a material that is heat resistant, water resistant, and transparent. Therefore, the heat-shrinkable tube 10 can be used to perform protection including rustproofing or the like of the shielding portion 7, and to visually confirm a condition of the tape-shaped metal foil 8 through the heat-shrinkable tube 10 from the outside.

FIGS. 3(A) to 3(C) show a manufacturing process of the shielded pipe 1 of this embodiment. First, the pipe body 6 is shaped (see FIG. 3(A)). Examples of the shaping method include a method in which the pipe body 6 is shaped into a predetermined bent shape from the outset, and a method in which the pipe body 6 is shaped into a straight pipe shape by extrusion molding or the like and then shaped into a predetermined shape by being locally heated.

Next, the tape-shaped metal foil 8 is spirally wound over the entire length between one end side to the other end side of the pipe body 6 obtained in the above-mentioned manner. During the winding, the tape-shaped metal foil 8 adheres to the outer circumferential surface of the pipe body 6 with the lateral edges overlapping each other. Accordingly, the entire outer circumferential surface of the pipe body 6 is covered with the tape-shaped metal foil 8 without being exposed (see FIG. 3(B)).

The heat-shrinkable tube 10 sheathes the pipe body 6 provided with the shielding portion 7 in this manner from one end side in the longitudinal direction, and covers the range of substantially the entire length of the pipe body 6. Thereafter, when the entire heat-shrinkable tube 10 is heated, the heat-shrinkable tube 10 is shrunk and covers the outer circumferential surface of the shielding portion 7 in intimate contact therewith while following the outline shape of the pipe body 6. In this manner, the desired shielded pipe 1 is produced.

The following describes effects of the shielded pipe 1 produced as described above.

(1) Since the pipe body 6, which is a main portion of the shielded pipe 1, is made of a synthetic resin material, its weight can be reduced compared with a conventional shielded pipe whose main portion is made of metal.

(2) For the reason noted in (1), the bending processing can be easily performed, and the degree of freedom with regard to the shape and the accuracy of dimensions can be improved.

(3) Since the shielding portion 7 is configured by spirally winding the tape-shaped metal foil 8, the shielding portion 7 can be easily configured regardless of the shape of the pipe body 6.

(4) Since the protective portion 9 is formed of the heat-shrinkable tube 10, the protective portion 9 is not damaged from peeling compared with cases where the protective portion 9 is constituted by a coating or the like, and thus a high protective function for the shielding portion 7 can be exhibited. Moreover, even if a portion of the heat-shrinkable tube 10 tears and the shielding portion 7 is eroded by water infiltrating through the torn portion, since the pipe body 6 is made of a resin, it is possible to prevent the breakage of the pipe body 6 unlike in cases where a shielded pipe made of metal is used.

(5) It is easy to adjust the shielding function by adjusting the thickness of the tape-shaped metal foil 8 or the number of times of winding the tape shaped metal foil 8.

Embodiment 2

FIG. 5 shows Embodiment 2 of the present invention. Whereas the shielding portion 7 is constituted by the tape-shaped metal foil 8 in Embodiment 1, the shielding portion 7 of Embodiment 2 is configured by winding a plurality of sheet-like metal foils 20 around the outer circumferential surface of the pipe body 6. In the same manner as in Embodiment 1, the sheet-like metal foil 20 also adheres to the outer circumferential surface of the pipe body 6 with a bonding layer provided on their back surfaces.

In this embodiment, a plurality of types of the sheet-like metal foils 20 that differ in a width dimension (width in the front rear direction of the vehicle) are used. In particular, in the pipe body 6, sheet-like metal foils 20 having a longer width are attached to a long straight region, and sheet-like metal foils 20 having a shorter width are successively seamed together and attached to a bent region. Accordingly, the shielding portion 7 can be configured so as to follow the outline shape of the pipe body 6. Moreover, the time to wind the sheet-like metal foils 20 is shorter than the time to spirally wind the tape-shaped metal foil 8. Therefore, work efficiency can be improved. In addition, it is easy to adjust the shielding function by adjusting the thickness of the sheet-like metal foils 20 or the number of times of winding the sheet-like metal foils 20.

The other configurations are the same as those of Embodiment 1, and therefore, the same operations and effects can be exhibited.

Other Embodiments

The present invention is not limited to the embodiments, which have been described using the foregoing description and the drawings, and, for example, embodiments as described below are also encompassed within the technical scope of the present invention.

(1) Although the metal foils 8 and 20 in which a bonding layer was laminated on their back surfaces were shown as examples in the foregoing embodiments, the metal foils 8 and 20 having no bonding layer may alternatively adhere to the pipe body 6 via a glue.

(2) Although a case where the tape-shaped metal foil 8 is spirally wound with substantially no intervals was shown in Embodiment 1, the tape-shaped metal foil 8 may be wound with intervals as long as an appropriate shielding function can be obtained.

(3) Although the protective portion 9 was formed of the heat-shrinkable tube 10 in the foregoing embodiments, the protective portion 9 may be formed with the following methods instead of or together with that method.

(i) A tube made of a soft resin or rubber may sheathe the pipe body 6 provided with the shielding portion 7.

(ii) Similarly, a protective film may be formed on the outer circumferential surface of the shielding portion 7. For example, the shielding portion 7 may be coated with a coating by applying a paint onto the shielding portion 7, or a film may be formed by vapor deposition using a synthetic resin, metal, or the like as a vapor deposition material.

(4) Although the case where the pipe body 6 is formed of a synthetic resin material was shown in the foregoing embodiments, the synthetic resin material may be mixed with a conductive resin material and shaped.

Accordingly, improvement in the shielding function can be expected.

(5) Although a case where the shielded pipe 1 is constituted by one seamless pipe was shown in the foregoing embodiment, the shielded pipe 1 may be configured by connecting a plurality of pipes. (6) It is preferable to color the heat-shrinkable tube orange to indicate that high-voltage electrical wires are inserted into the heat-shrinkable tube.

LIST OF REFERENCE NUMERALS

1 . . . Shielded pipe

6 . . . Pipe body

7 . . . Shielding portion

8, 20 . . . Metal foil

9 . . . Protective portion

10 . . . Heat-shrinkable tube 

1-4. (canceled)
 5. A shielded pipe for a vehicle, the shielded pipe being configured to receive an electric wire, and the shielded pipe comprising: a pipe body made of a synthetic resin material; a shielding portion formed by winding a plurality of sheet-like metal foils around an outer circumferential surface of the pipe body; and a protective portion formed on an outer circumference of the shielding portion, wherein the shielding portion is formed by winding the plurality of sheet-like metal foils around the pipe body with the sheet-like metal foils being successively seamed together; the pipe body includes a straight region and a bent region; the sheet-like metal foils having a longer width are wound around the straight region; and the sheet-like metal foils having a shorter width are wound around the bent region.
 6. The shielded pipe according to claim 5, wherein the protective portion is a heat-shrinkable tube that sheathes the pipe body.
 7. The shielded pipe according to claim 5, wherein the protective portion is a film that is laminated on the outer circumferential surface of the shielding portion, the film having a rustproofing function. 